New Delhi: At the ‘India SaniTech Forum’ on Saturday, innovators showcased technologies that they have developed with the aim of putting an end to manual scavenging. The solutions included a robot that can go down a manhole to clean the sludge; remote controlled devices that can break down sludge that has turned solid; and monitoring systems that can send alerts if the gases inside the manhole turn toxic.
Even though employment of a person to manually clean sewers or septic tanks is prohibited by law, several thousand continue to be employed as manual scavengers. According to the Rashtriya Garima Abhiyan, 600 people have died in the last one-and-a-half years while working as manual scavengers. In September alone, 11 workers died while cleaning septic tanks and sewers.
A group of young engineers from Kerala have designed a robot which they have named ‘Bandicoot’. The robot is capable of entering and cleaning sewers and manholes. “The idea was to end the need for a human being to enter a manhole. This robot can enter a manhole and clean it thoroughly,” said Rashid K., one of the four founders of their startup ‘Genrobotics’ which has designed ‘Bandicoot’.
Once inside the manhole, the robot spreads its arms and scoops out the solid and liquid filth that often leads to blockages inside sewers. Its movements are remote controlled by a device attached to it. The robot can also detect and warn against toxic gas inside a manhole. Currently, one unit of ‘Bandicoot’ costs Rs 12 lakh and the innovators are working on reducing the cost.
Some units of the robot have been deployed by three municipal corporations in Kerala, Tamil Nadu and Andhra Pradesh. “The response has been good. The robot has worked effectively,” said Rashid.
Another innovation is a device designed by a young engineer, Divanshu Kumar, from the Indian Institute of Technology, Madras. The device is a cylindrical hull which can be lowered into a septic tank. It can clean the sludge that settles at the bottom of the septic tank after years of accumulation of faecal matter. Kumar, the 21-year-old developer of the instrument claims that it can even break down sludge that turns solid, almost concrete. “It has a strong mechanism and is able to cut through even solid sludge,” he said.
Having only recently designed the instrument, Kumar has so far only tested it in water. The tests yielded positive results. The technological challenge currently for Kumar is to ensure that the instrument is able to enter septic tanks, where the gas can be toxic and not explode as the instrument runs on electricity. “This here is just a prototype. I am very close to a solution so that the instrument can enter a septic tank and not explode. It should be ready in a few months,” said Kumar.
Another innovator, Balakrishnan, is a former employee of the Hindustan Aeronautics Limited. After his retirement, he and another colleague, Germiya Ongolu, set up Ajantha technologies to try and solve the problem of manual scavenging in India. They have designed mechanical devices which detect toxic gases, clean sewers and septic tanks and eliminate the need for manual cleaning.
At the first stage is a gas detector module which is attached to a manhole and can send a text message after the levels of toxic gas inside reach alarming levels. Most of the deaths of workers while performing manual scavenging have occurred due to inhaling toxic gases that form inside sewers. The toxic gases can be harmful even if a worker is not entering the sewer and is only lowering instruments into it as the gases that emanate can cause skin diseases. If the levels of toxic gas are known, as this device is built to ensure, those risks can be mitigated.
Another device is a jet powered mechanical instrument which can clear obstructions and flush a sewer clean. “It is designed to work inside the sewer where it can pulverise the debris, waste water and sludge that has accumulated inside. The device is fitted with cutting blades which can cut through tough blockages. The water jet is able to spin the turbine to propel the device forward inside the sewer,” said Balakrishnan.
The instrument has been designed for sewer pipes of varying diameters – 200, 250, 300 and 400 millimetres. In the tests conducted, it has been found to be performing satisfactorily.
“We have had several meetings with the Telangana government. They have tested the products and their response has been positive. It is likely that they will soon order some of the products and will be using them,” said Balakrishnan.
Balakrishnan and Ongolu are also working on designing a full body suit that workers employed in the task of cleaning sewers can wear to ensure that they remain protected against toxic gases. “Even those workers who don’t actually enter sewers and remain at the level of the road, are exposed to gases because they flow out as soon as the manhole is opened. So, we are designing a suit that they can wear which will ensure that they are protected,” said Balakrishnan.